Stationary boiler



Feb. 10, 1931.

v. z CARACRISTI STATIONARY BOILER Filed Jan. 8, 1927 2 Sheets-Shee 1 INVENTOR MORNEYS Feb. 10, 1931-. v. z. CARACRISTI S TA'II ONARY BOILER 8, 1927 2 Sheets-Sheet 2 Filed Jan.

INVENTOR ,l/ ATTORNEY! Patented Feb. 10, 1931 UNITED STATES PATENT OFFICE VIBGINIUS Z. CARACRISTI, O1 BRONXVILLE, NEW YORK, ASSIGNOR TO INTER- NATIONAL OOMBUSTION ENGINEERING CORPORATION OF DELAWARE CORPORATION, OF NEW YORK, N. Y., A.

STATIONARY BOILER Application fled January 8, 1927. Serial No. 159,805.

This invention relates to'stationary boilers, and is especially useful where fuel is burned in a finely divided liquid or gaseous form, as, for example, in the form of pulverized coal.

One of the primary objects of the invention is to EIOVldt-B a stationary boiler installation capa le of being fired at the very high rates such as are obtained in locomotive boilers.

Still another object of the invention is to obtain very high capacities in the stationary boiler, as compared to present practice, and this with high eificiency.

Other and more specific objects will appear in connection with the following description of the best form of the invention now known to me.

In the drawings Fig. l is a vertical section through a boiler embodying the preferred form of my invention.

Fig. 2 is a section taken on the line 2-2 of F g. 1 drawn on an enlarged scale.

Fig. 3 is a fragmentary section taken on the hne 3-3.of Fig. 1.

- Fig. 4 is a fragmentary section taken on the hue 44 of ig. 1, and

Fig. 5 is a section taken .on the line 5- -5 of Fig. 1..

Referring now to the Fi res 1,2 and 3, the reference character A enotes the combustion chamber beneath which is the ash.

pit B. To the rear of the combustion chainber is a lower or mud drum 7 above which is an up er drum 8, these two drums bein connecte b a vertical bank of tubes 9. front 0 the combustion chamber slightly above the level of the drum 7 is a drum 10 and above this, sli htly below the level of the drum 8, is anot er drum 11. The drum 11 is connected with the drum 8 by a plurality of slightly inclined tubes 12 which carry the roof, are orsheathing brick 13. The

drums 10 and 11 are connected by a plurality of pi 14 which constitute upcomers from the 10 to the drum 11, the tubes 12 constituting upcomers from the drum 11 to nected bg nally extending fins 15 on each of the two opposite sides, the tubes and fins cooperating to provide a substantially continuous metallic wall which defines the. front of the combustion space. This metallic wall is lined with an external sheating 16 which, by vir- 'tue of the cooling effect of the water wall, can be made very light.

Certain of the fins on certain of the tubes are interrupted so as to permit of the placing of the burners 17 which'feed the fuel to the furnace, it bein understood that there are a row of suc feed openings located above the drum 10, the number of burners being dependent upon the size of the particular installation.

Connecting the drum 7 to the drum 10 is a row of tu es 18. These tubes are spaced well apart, as shown, for exam le, in Figs. 2 and 3, in order to lpermit the re se particles gravitating out of t e fuel and flame stream to reely pass into the ash pit. At their front ends these tubes 18 are provided with fins 19;

The drum 7 and the-drum 10 are also congroups of tubes 0, which tubes are provide longitudinally of the tubes.

The groups of tubes C cooperate with the tubes 18 to provide upstanding hollow wall portions, the interior of which hollow wall portions opens into the space beneath the above the tubes 18. Air is admitted into the space 23 beneath the drum 10 and ,the up r ends of'the tubes 18 and the group of tn '0, suchair entering into the longitudinal channels provided by the group of tubes 0, from which space this air enters the combustion space through the ports 22 as will further appear. This air, in traversing the chamber 23, becomes initiall preheated be ore entering the cham ber 23 y any suitable form of air reheater.

Rising from the drum 7 to the rum 11 is a row of tubes 24'diagonall cuttin the com bustion space very much a ter the ashion of the circulation tubes employed in a locomotive boiler, which tubes connect the'front and with short fins 21 spaced apartpreheated, and may be rear water legs of the locomotive boiler. These tubes carry a refractory arch 25 composed of T-shaped bricks socketed on the tubes 24. These tubes have fins 26, as shown in Figure 4, and the legs 27 of the T-shaped bricks are adapted to project inwardly into the space between adjacent fins, in which connection it willbe observed that the tubes 24 are relatively widely spaced apart.

At the sides of the combustion chamber are tubular water walls D of substantially the same construction as the direct water wall. The finned tubes 28 constituting these side water walls have their ends expanded into the headers 29 and 30, which, in turn, are conected to the drums 10 and 11.

The operation is as follows:

The powdered coal with a portion of the air required for combustion is admitted through the, burners 17 in a substantially horizontal direction, and the fuel and flame stream takes the course indicated in Fig. 1. Enough air may enter with the fuel to institute ignition, and the balance of the air required for combustion is provided through the ports 22 already described. This air is preferably delivered under pressure as by a fan not shown) or by the maintenance of a di bustion chamber, and it will be seen that the jets of air entering the combustion chamber through the ports 22 will impinge upon the fuel and flame streams at relative right angles, producing a violent mixing and agitation, with a consequent violent and intense combustion which is com leted within a relatively short time. The rickwork of that portion of the side walls not covered b the side water walls and the arch subject bot the entering fuel and the fuel and flame stream to radiant heat which promotes both the ignition and the completion of combustion. The combustion of anycombustibles passing over the upper end-of the arch into the space above the arch is ensured by the heat radiated from the arch, so that by the time the first pass of the bank of tubes 9 is reached, combustion will have been completed, and the bank of tubes 9 will function as an economizer section.

It will be seen that the provision of the groups of tubes C and the diagonal row of tubes 24-. divides the combustion chamber into what is, in effect, a plurality of combustion zones, and the manner of introducing and burning the fuel produces violent combustion in each of the combustion zones, in consequence of which I am enabled to thoroughly burn a larger amount of fuel per unit of volume than is possible in a structure not provided with independently functioning zones, for the reason that stream line combustion is prevented, due to the relative small size 0 each combustion zone unit, while, at the same time, high efficiency is obtained. No trouble erential vacuum condition in the comwill be encountered because of slagging of the refuse particles for such as precipitate downwardly in the spaces between the tubes 18 will remain in granular readily removable form. By virtue of the high rate at which the side water walls and the tubes 24 will absorb heat, there will be no slag deposit thereon,-and by the time the waste gases reach the bank of tubes 9 their temperature will be reduced below the point at which the ash carried in suspension therein will fuse, in consequence of which there will be no slagging trouble encountered in the rear.

I prefer to terminate the fins 26 some distance above the drum 7. In this connection it is not undesirable to have some portion of the gases pass around the lower end of the arch. This amount, however, should be comparatively small, and the length of the fins 26 should be determined in accordance with the needs of the particular installation.

It will follow, from what has been said, that the boiler will develop very high capacities with an amount of evaporating surface quite small in comparison to the number of tubes which would be required in accordance with standard practice to develop the same amount of steam.

What I claim is:

1. In a stationary boiler-furnace, boiler elements arranged to form the lower part of the boiler-furnacesubstantially into a plurality of lateral separately functioning combustion zones, and means for feeding finely divided fuel and air into the lower part of the combustion space for intense combustion.

2. In combination, a pair of laterally spaced upper drums, a pair of laterally spaced lower drums, the said upper drums being positioned respectively substantially above the lower drums, tubes connecting the lower drums, tubes connecting the upper drums, tubes connecting each upper drum with its respective lower drum, whereby a box-like combustion chamber largely defined by tubes is provided, tubes diagonally connectin a lower drum with an upper drum and ba ed to divide the combustion chamber into lower and upper communicating combustion spaces, and means for introducing'fuel into the lower space.

3.In combination, a pair oflaterally spaced upper drums, a pair of laterally spaced lower drums, the said upper drums being positioned respectively substantially above the lower drums, tubes connecting the lower drums, tubes connecting the upper drums, tubes connecting each upper drum with its respective lower drum, whereby a box-like combustion chamber largely defined by tubes is provided, tubes diagonally connecting a lower drum with an upper drum f and baffled to divide the combustion chamber into lower and upper communicating combustion spaces, and means for introducing fuel and combustion air into thelower space under conditions to produce violent mixing and burning. g

4. In a pulverized coal burnin boiler combustion chamber, means introduclng a stream of pulverized coalthereinto, a oup of tubes extending approximately para lel to the line of fuel admission and to one side of the fuel and flame stream, said tubes being arranged to constitute in eflect a channel with lateral openings, and means whereby combustion air may be supplied to the channel to pass laterally thereout of through said openings.

5. In a finely divided fuel burning boiler furnace, a group of finned tubes therein arranged to of themselves constitute a channel for combustion air, the fins being interrupted to provide orts.

6. In a nely divided fuel burning boiler furnace, a tubular water screen in the lower portion of the furnace, and other tubes grou ed to form channels for combustion air whicli rise substantially above the screen and divide the lower part of the combustion space above the screen, said channels having openings communicating with the combustion space.

In testimony whereof I have hereunto si ed m name.

gn IRGINIUS Z. CARACRISTI. 

